In a 2 quart measuring cup or casserole dish mix sugar and corn syrup.,Microwave, uncovered on High for 4 minutes, stirring at half time.,Mix in the peanuts and butter and microwave, uncovered on High for 3 1/2 to 4 minutes, until pale,brown. Quickly stir in the vanilla and baking soda.,Pour onto a buttered baking sheet and spread as thin as possible with a buttered spatula.,______,When cold, crack into pieces.